NBME Pediatrics 3

Question 1

A premature infant born at 28 weeks develops increasing respiratory distress immediately after birth. CXR shows diffuse ground-glass opacities bilaterally. The deficiency responsible is:

Accepted Answer

Surfactant

Answer

Respiratory distress syndrome in premature infants results from surfactant deficiency, which reduces alveolar surface tension.

Question 2

A 6-week-old male presents with non-bilious projectile vomiting after every feeding. He is hungry immediately after vomiting. Palpation reveals an olive-shaped mass in the epigastrium. Next step?

Accepted Answer

Abdominal ultrasound

Answer

Abdominal ultrasound is the gold standard to confirm pyloric stenosis by demonstrating pyloric muscle thickness ≥4 mm and length ≥16 mm.

Question 3

A 2-year-old presents with a barking cough, stridor, and low-grade fever. Neck X-ray shows a 'steeple sign.' Most appropriate initial management?

Accepted Answer

Dexamethasone

Answer

Dexamethasone is the first-line treatment for croup (laryngotracheitis), reducing subglottic edema and duration of symptoms.

Question 4

A neonate born to a mother with poorly controlled diabetes develops jitteriness, hypotonia, and poor feeding at 2 hours of life. Blood glucose is 28 mg/dL. First step?

Accepted Answer

IV D10W bolus

Answer

Symptomatic neonatal hypoglycemia requires immediate IV dextrose bolus (D10W 2 mL/kg) to rapidly restore euglycemia.

Question 5

A 13-year-old girl presents with primary amenorrhea, short stature, webbed neck, and a widely spaced chest with shield-like appearance. Karyotype most likely shows:

Accepted Answer

45,X

Answer

Turner syndrome (45,X) classically presents with short stature, webbed neck, shield chest, and primary ovarian insufficiency.

NBME Practice Test

NBME Practice Test

NBME Pediatrics 3